Low-cost dual-polarized radiating elements and related base station antennas
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Solution Overview
Problem
Base station antennas face issues with scattering of RF energy due to low-band radiating elements interfering with mid-band and high-band arrays, leading to degraded performance and increased wind loading, which is exacerbated by the need for cost-effective designs within network operator width limits.
Innovation Solution
The use of dielectric-supported sheet metal dipole arms with capacitive and galvanic connections on a feed stalk printed circuit board, along with meandered trace segments for impedance matching, reduces scattering and cost while maintaining performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If low-band radiating elements are used in base station antennas, then cost-effective designs are achieved, but scattering of higher frequency band RF energy occurs leading to degraded performance
Solution Approach 1:
A dielectric member is introduced as an intermediary between the low-band radiating element and the mid-band/high-band radiating elements. This dielectric member has RF transparency characteristics that allow higher frequency RF energy to pass through without being scattered by the low-band element, thus mediating the interaction between different frequency bands and eliminating the performance degradation while maintaining cost-effectiveness
2Adaptability or versatility
If multiple linear arrays are included to support multiple frequency bands, then service coverage is improved, but wind loading increases
Solution Approach 1:
The low-band radiating element is positioned behind the mid-band and high-band radiating elements, creating a nested configuration where multiple frequency band arrays are stacked in depth rather than spread horizontally. This nesting approach allows multiple linear arrays to coexist in a compact space, improving service coverage while reducing the horizontal footprint and associated wind loading
3Volume of moving object
If low-band radiating elements are positioned behind mid-band and high-band arrays, then space is optimized, but scattering of higher frequency RF energy is exacerbated
Solution Approach 1:
The dielectric member is positioned between the low-band radiating element and the mid-band/high-band radiating elements to act as a mediator. It provides RF transparency that prevents the low-band element from scattering higher frequency RF energy, thus resolving the harmful scattering effect while maintaining the space-optimized nested configuration
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively suppresses higher frequency band RF scattering, improves beam shape and gain, and reduces wind loading, achieving cost-effective and performance-enhanced base station antennas.
Implementation Method 1
a feed stalk printed circuit board, and a coupling printed circuit board that is mounted on the feed stalk printed circuit board and configured to capacitively couple RF signals between the feed stalk printed circuit board and the sheet metal dipole arms
Implementation Method 2
first through fourth sheet metal dipole arms on the dielectric support
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Radiating elements comprise a dielectric support, first through fourth sheet metal dipole arms on the dielectric support, and a feed stalk printed circuit board. The feed stalk printed circuit board includes a first RF transmission line that has a first signal conductor that is coupled to the first sheet metal dipole arm through at least a first capacitive connection and a first ground conductor that is coupled to the second sheet metal dipole arm through at least a second capacitive connection and a second RF transmission line that has a second signal conductor that is coupled to the third sheet metal dipole arm through at least a third capacitive connection and a second ground conductor that is coupled to the fourth sheet metal dipole arm through at least a fourth capacitive connection.